What Can a Metal Catalyst Do with Allenes? One‐Step Formation of Steroid Scaffolds from Readily Available Starting Materials

The beauty and power of transition-metal-catalyzed reactions has been demonstrated by the one-step synthesis of steroid scaffolds from readily available allenes. The best results (57–73 % yield) were obtained using trans-[RhCl(CO)(PPh3)2] as the catalyst in toluene (see scheme; E=CN, CO2Me, SO2Ph, Ts=toluene-4-sulfonyl).